Technical solutions are known for cleaning electrodes from dust where the cleaning device travels during cleaning relative to a fixed ionizing electrode or a group of electrodes (e.g. see WO 2012/176099 and U.S. Pat. No. 8,106,367).
The cleaning device disclosed in WO/2012/176099 is formed either as a layer of porous fiber material or a layer of fine-dispersed balls arranged between two grids with cells whose size is bigger than the diameter of the ionizing electrode. At the same time the entire device is designed as a nonstandard solenoid where the permanent magnet and the cleaning device mount are shifted with respect to the fixed coil.
One disadvantage of such a device is the impossibility to use conventional solenoids which increases the complexity of the device.
Another disadvantage is the complicated procedure of selection of the thickness of the porous fiber material or of the diameter of the fine-dispersed balls and also the grids for different diameters of ionizing electrode.
U.S. Pat. No. 8,106,367 discloses an ionizer wherein a fixed array of planar electrodes is wiped between adjacent coils of a spring fixed to a manual slider which functions as a cleaning element. The spring axis is parallel to a line normal to the plane of the electrodes, which are cleaned as the spring is moved manually toward the electrodes while maintaining a constant distance between the spring axis and the line normal to the plane of the electrodes. Such a device cannot be used with a standard ionizing electrode whose tip diameter is much smaller than the diameter of the shank of the electrode.
U.S. Pat. No. 8,957,571 discloses an ionizing electrode with a cleaning mechanism wherein the cleaning mechanism is formed as a fixed tube with the ionizing electrode connected to the solenoid core travelling inside it.
A drawback of the device is the impossibility to use it for ionizing electrodes with needle-type ionizing edges or for ionizing electrodes made of materials such as tungsten or brittle materials such as silicon.
A problematic issue common to all the known devices is the removal of debris from the local cleaning spot.